On Tue, Jun 06, 2023 at 05:17:05PM -0700, Andrew Pinski via Gcc-patches wrote:
> While working on `bool0 ? bool1 : bool2` I noticed that
> zero_one_valued_p does not match on the constant zero
> as in that case tree_nonzero_bits will return 0 and
> that is different from 1.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
>
> gcc/ChangeLog:
>
> * match.pd (zero_one_valued_p): Match 0 integer constant
> too.
> ---
> gcc/match.pd | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index f9cbd757752..f97ff7ef760 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -1983,11 +1983,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (bit_not (bit_not @0))
> @0)
>
> +/* zero_one_valued_p will match when a value is known to be either
> + 0 or 1 including the constant 0. */
> (match zero_one_valued_p
> @0
> (if (INTEGRAL_TYPE_P (type) && tree_nonzero_bits (@0) == 1)))
So perhaps instead change this to
&& wi::leu_p (tree_nonzero_bits (@0), 1)
?
> (match zero_one_valued_p
> truth_valued_p@0)
> +(match zero_one_valued_p
> + integer_zerop@0
> + (if (INTEGRAL_TYPE_P (type))))
>
> /* Transform { 0 or 1 } * { 0 or 1 } into { 0 or 1 } & { 0 or 1 }. */
> (simplify
Jakub
